Field of the Invention
The present invention relates to a gas turbine engine in which air compressed by a compressor is mixed with a fuel and combusted in a combustion chamber, and a turbine, which is supplied with a high-temperature combustion gas generated by combustion of the fuel, includes nozzle guide vanes on an upstream side and turbine blades on a downstream side.
Description of the Related Art
U.S. Pat. No. 5,545,004 describes a technique for protecting components of a gas turbine engine from thermal damage by preventing a high-temperature combustion gas flowing through a main flow passage 16 in a turbine duct of the engine from leaking to a low-temperature space 18 in the engine. In this technique, a high-temperature gas recirculation pocket 14 is formed on a radially inner side of an annular platform 25 of stator vanes (nozzle guide vanes) 24 disposed in the main flow passage 16 in the turbine duct. In this structure, the combustion gas flowing through the main flow passage 16 and air in the low-temperature space 18 are introduced into the high-temperature gas recirculation pocket 14, are mixed and circulated, and are then returned to the main flow passage 16, thereby preventing the hot gas from leaking directly to the low-temperature space 18.